Through relatively recent technological innovations, computer systems have become dramatically smaller and more portable. Even very powerful personal computers (PCs), for example, are small enough to sit on the desk at work. Smaller still are lap top computers and notebook computers. There are computer terminals which are small enough to be mounted in a vehicle, such as a delivery truck. Still smaller are hand held terminals, which are typically used for their portability features, allowing a user to carry the terminal in one hand and operate it with the other.
In addition, there is a trend toward offering consumers electronic devices that include some sort of computer system, e.g., a microprocessor. Usually, these computer systems not only control the operation or function of the consumer device, but also provide some interface for a user or operator to control certain functions or parameters according to actual needs. It is in the nature of these consumer devices that they do not have a full user-interface like a computer with display and keyboard. It is not likely that a dishwasher, for example, will ever have such a full user-interface. In some cases the interface is limited due to space constraints (a typical example for this is a wrist watch), while in other cases the interface is limited to keep the cost of manufacturing low, while still in other cases the processing power of the computer system, or the constrained memory space, limits the interaction between the user and system.
Many of today's devices have an inadequate user-interface. A typical example is a compact disk (CD) player which allows programming of CD titles using a small four button-control. Programming of such a CD player is very cumbersome because one needs to use the buttons to move through the entire alphabet to select letters and/or numbers. Another example is a wrist watch that allows the user to enter phone book entries, appointments, and to-do items. Typically, the keyboard includes a very limited number of keys. Furthermore, the display is small and its resolution limited. Certain keys have to be pressed several times to reach special characters, or to activate special functions. Yet another example is a personal digital assistant (PDA) with a touch sensitive screen. In this case the screen occupies most of the device's surface and there are very few buttons, if any. Some functions are easily accessible using a pointing device, but other functions have to be selected or activated flipping through several layers of menus, for example. Other examples are telephones, vending machines, microwave ovens, mobile phones, etc. For the purposes of the present description these devices are referred to hereinafter as user-interface limited devices.
Currently there are a few approaches using a personal computer (PC) to run better user-interfaces, e.g. the “Nokia Cellular Data Suite” for mobile phones allows the entry of phone book data. The Cellular Data Suite is a hardware and software package from Nokia designed for cellular phones. Another example is a wrist-watch that has an IR-communication feature (such as the Casio PC Unite Data Bank Watch, HBX-100B-1) used to connect to a PC.
There are many other examples of user-interfaces that are severely lacking for various reasons, the most prominent of which are size and cost constraints. Often such user-interface restrictions make the respective devices less useful for their owners than they could be.
It would thus be useful to have a way to unleash the full potential of all these devices and to program and configure them much more conveniently, thereby making them more useful to their users.
There is growing demand in the industry to offer devices that are ‘open’ in the sense that a user has access via an interface to the device's processor or other components. An ideal ‘open’ device would be fully controlled by the user, preferably within well-defined rules to prevent misuse or destruction of the device itself.
In addition, there are a growing number of devices that are network enabled, which means that they can communicate with one or more other devices via a network. This can be achieved using physical connections, such as cables or fibers, for example. As these devices get smaller, however, it becomes desirable to replace the physical connections with wireless connections (e.g. body networks, radio frequency connections, or infrared connections), since physically connecting the devices by means of cables or fibers severely reduces the efficiency gained by making the units smaller. Ad-hoc wireless connections are required where devices move around, enter an area and exit the area. The term ad-hoc refers to the need for frequent network reorganization.
In addition, there are many different known communications protocols or standards that have been developed and designed (and continue to be developed and designed) directed at communication between devices or subsystems. Hereinbelow, some wireless communications protocols or standards will be mentioned. There are many fiber or cable-based, standardized approaches that are suited for such communication as well.
GTE Corporation has developed a short-range radio-frequency (RF) technique which is aimed at giving mobile devices such as cellular phones, pagers and hand-held personal computers (PCs) a smart way to interact with one another. GTE's technique is tentatively named Body LAN (local area network). The original development of Body LAN was via a wired vest with which various devices were connected (hence the name Body LAN). This then developed into to an RF connection.
Xerox Corporation has developed a hand-held computing device called PARC TAB. The PARC TAB is portable yet connected to the office workstation through base stations which have known locations. The PARC TAB base stations are placed around the building, and wired into a fixed wired network. The PARC TAB system uses a preset knowledge of the building layout and the identifiers of the various base stations to determine the strongest base station signal for a PARC TAB portable device. A PARC TAB portable device has a wireless interface to the base stations. The PARC TAB system assumes that the PARC TAB portable device is always connected to the network infrastructure. The location of each portable PARC TAB device is always known to the system software. The base stations establish regions and are connected to power supplies. PARC TAB communication systems have a star topology.
In an attempt to standardize data communication between disparate PC devices, several companies, including Ericsson, IBM, Intel, Nokia, and Toshiba have established a consortium to create a global standard for wireless RF-based connectivity between fixed, portable and mobile devices. There are many other companies adopting the proposed standard. The proposed standard is called Bluetooth and comprises architecture and protocol specifications ranging from the physical layer up to the application layer. The Bluetooth standard contemplates allowing users to connect a wide range of devices easily and quickly, without the need for cables, expanding communications capabilities for mobile computers, mobile phones and other mobile devices. The Bluetooth operating environment is not yet fully defined, but similarities are expected with the IrDA (Infrared Data Association) specification and the Advanced Infrared (AIr) specification. It is not unreasonable to expect that the Bluetooth standard will eventually incorporate aspects of the IEEE standard 802.11 and/or HIPERLAN, as promulgated by the European Telecommunications Standards Institute (ETSI).
Bluetooth radio technology provides a standard protocol suitable for forming small private ad-hoc groupings of connected devices away from fixed network infrastructures. Bluetooth makes a distinction between a master unit—which is a device whose clock and hopping sequence are used to synchronize all other devices—and slave units in the same network segment. In other words, the Bluetooth approach is centralized. A query-based discovery design is used for finding Bluetooth devices with an unknown address. Queries are also centralized at a registry server. Further details can be found in Haartsen, Allen, Inouye, Joeressen, and Naghshineh, “Bluetooth: Vision, Goals, and Architecture” in the Mobile Computing and Communications Review, Vol. 1, No. 2. Mobile Computing and Communications Review is a publication of the ACM SIGMOBILE.
HomeRF (based on Shared Wireless Access Protocol (SWAP)) is another example of a prospective operating environment protocol which can be used to connect devices. A HomeRF Working Group was formed to provide the foundation for a broad range of interoperable consumer devices by establishing an open industry specification for wireless digital communication between PCs and consumer electronic devices anywhere in and around the home. The working group, which includes the leading companies from the personal computer, consumer electronics, peripherals, communications, software, and semiconductor industries, is currently developing a specification for wireless communications in the home called the SWAP. The HomeRF SWAP system is designed to carry both voice and data traffic and to interoperate with the Public Switched Telephone Network (PSTN) and the Internet. It operates in the 2400 MHz band and uses a digital frequency hopping spread spectrum radio. The SWAP technology protocol being developed is being derived to some extent from extensions of existing cordless telephone (DECT) and wireless LAN technology to enable a new class of home cordless services. It envisions supporting both a time division multiple access (TDMA) service to provide delivery of interactive voice and other time-critical services, and a carrier sense multiple access/collision avoidance (CSMA/CA) service for delivery of high speed packet data. The SWAP system is contemplated to operate either as an ad-hoc network or as a managed network under the control of a connection point. In an ad-hoc network, where only data communication is supported, all stations will be equal and control of the network will be distributed between stations. For time critical communications such as interactive voice, the connection point—which provides the gateway to the PSTN—will be required to coordinate the system. Stations will use the CSMA/CA to communicate with a connection point and other stations. Further details about HomeRF can be found at the Home Radio Frequency Working Group's web site http://www.homerf.org. The SWAP specification 1.0 is incorporated by reference in its entirety.
There are several other known protocols and techniques that allow communication between two or more devices. The above described Bluetooth radio technology and HomeRF approach are prominent wireless examples.